Chipping in my two cents here late in the game.
And now that I've typed this out, it's turned into a bit of a lengthy unhinged rant, but here we go:
I'm a little annoyed that, in the end, a press conference was the reason Shanahan decided to shit-can Dubas. But for an altogether different reason than Montana---I don't think Shanahan should have ever entertained bringing him back in the first place because Dubas richly deserved to be fired purely based on his job performance. And I'm pretty happy to see him go.
He does seem like a genuinely decent human being in a league that doesn't have enough of those. And in terms of social causes, Dubas seems to be pretty closely aligned to my own sensibilities. And I appreciate both those things. But the bottom line is that as a GM, he didn't end up being the kind of manager he was advertised to be. He was supposed to be a forward-thinking, analytical GM who'd keep our core together while surrounding them with a strong supporting cast through a combination of a strong focus on the draft, developing from within, smart cap management and identifying market inefficiencies on the trade and free agent markets.
And...that just didn't happen.
As far as smart adds through free agency goes, some people are trying to retcon this into a recent development that Shanahan is surely responsible for, but right from the start of Dubas's tenure as GM, he's had an over-fondness for shitty, low-event, no-talent veteran pluggers. At first we blamed Babcock for this, but he kept right up with it after getting his own hand picked, supposedly forward-thinking coach. He did also add to our depth a skilled midget or analytics darling here and there as a project, but to a man these guys were failures. Really his only major success in free agency was signing TJ Brodie to a market-value deal, and to a lesser degree having three Toronto boys knock on his door and ask if they could pretty please play here at home for minimum wage (Bunting, Spezza, Giordano).
As far as his cap management goes, a team with the Leafs' cap constraints rolling into this year's playoffs with Alex Kerfoot, Calle Jarnkrok, Justin Holl and Matt Murray taking up a combined $12M and change is a cap management crime against humanity. The Tavares contract also looms as an obvious mistake that's only getting worse with time, as some of us predicted back when it was first signed. We're also staring down the barrel of losing one of the best players in the NHL at the age of 26 (or in the best-case scenario, giving him a significant raise) because Dubas is the only GM in the league who paid his star player the kind of top dollar AAV that usually comes with a max-term deal while only managing to get him to commit for five years. Not to mention the way Mitch bent him over a barrel in his negotiations, or how he wiped out basically an entire season of Nylander's prime only to end up giving him pretty much the deal Willy was asking for in the first place.
And in terms of drafting and development...somehow once Dubas graduated from the Marlies to the big job, we became an organization terrified to give any of our best young players trust, patience and real opportunities at the NHL level. Sandin getting dumped, Lilly & Timmins getting benched and nobody on the Marlies getting a sniff of an NHL job after the mid-point of the season were the latest egregious examples of this.
He also did the familiar Toronto GM thing where he completed every off-season with glaring holes still present on his roster, and left himself scrambling to plug them by shooting a goddamn firehose of draft picks and futures down the drain for rentals at the trade deadline. That he might've plucked some worthwhile players out of the draft with what few, later picks he held on to doesn't excuse this, IMO. And the jury is still out on the quality of his picks, considering Rasmus Sandin (RIP) and Pontus Holmberg were the only Dubas picks to play 20 or more games in the NHL this year.
Anyway, tl;dr---as Presto succinctly put it a while back---Dubas just turned out to be Burke with glasses (though minus the ability to win a trade involving players off his NHL roster). So while I totally understand anyone having doubts about Shanahan or being worried about where we go from here, I don't really understand mourning Dubas's departure. His time was up and he had to go, even before he all but begged Shanahan to fire him on live television.